On a smoke break in the Loop Monday, computer programmer William Paxson watched hundreds of thousands of immigrant-rights marchers press down Jackson Boulevard and pronounced their show of force impressive but futile.

"I don't think this is going to do them any good," said Paxson, of Crystal Lake, predicting the rally would backfire against those seeking to legalize millions of undocumented immigrants. "I think most people are happy that they're here, but want them to be out of sight and out of mind."

The goal of demonstrations here and across the nation Monday was to persuade ambivalent citizens like Paxson that illegal immigrants play a vital role in the United States. and that they need and deserve to be allowed out of the shadows.

But it will take weeks or months to determine whether demonstrators were preaching to the choir or demonstrating resolve and power that will sway doubters and decision-makers. Polls show Americans hold mixed views about the fate of illegal immigrants, as well as their impact on and contributions to the nation.

Reflecting that divide, Congress is deadlocked over two very different approaches to resolving the illegal immigration debate--one punitive and the other more forgiving.

On Capitol Hill, officials said the rallies were unlikely to sway senators and congressmen who have staked out positions.

That group included U.S. Rep. Melissa Bean, a freshman Democrat from Barrington now facing a tough re-election fight in her conservative district. Bean was one of the few Democrats to vote in December with majority Republicans for a House measure to crack down hard on illegal immigrants already here.

"The first step to addressing both illegal immigration and homeland security is strengthening our borders," said Bean.

The demonstrations were met with strong criticism on talk radio, a galvanizing force for conservative activists.

"Law-abiding citizens and most Americans have got to stand up for what the law is," said Sean Hannity on his nationally syndicated show. "You can't expect people to obey new laws if they don't obey the old ones."

Congressional officials said the demonstrations could make it harder to find some middle ground between the House measure and a pending Senate bill that would combine a crackdown on the hiring of undocumented workers with a path toward legal status for many.

Even top Democrats were lukewarm about the rallies. A spokesman for Senate Democratic leader Harry Reid of Nevada said, "He's more focused on trying to pass a good, comprehensive immigration bill."

Sen. Lamar Alexander (R-Tenn.) referred to the demonstrations Monday as he introduced a resolution demanding that the Pledge of Allegiance and national anthem be in English.

"As part of these demonstrations, a new version of our national anthem, "The Star-Spangled Banner," has been produced--in Spanish," Alexander said. "We wouldn't recite the pledge in French, or German, or Russian, or Hindi, or even Chinese. And we shouldn't sing the national anthem in Spanish, or any other foreign language."

The congressional debate and heightened activism over reform have vaulted immigration concerns to national prominence.

In mid-March, a Gallup Poll found that just 6 percent of Americans considered it a major issue. That number jumped to 19 percent in a follow-up Gallup survey in mid-April, second on the list of American concerns behind the Iraq war.

Gallup Poll editor-in-chief Frank Newport said polls consistently show Americans open to allowing illegal immigrants now here to remain in this country, though with significant restrictions. At the same time, the polls also reflect heightened anxiety about the economic and security impact of illegal immigrants and porous borders.

That inconsistency is making it hard for elected officials to read political tea leaves and reach consensus.

Many bystanders who watched the marchers Monday also reflected that conflict. In New York, Lynne Kershaw recalled the nation's immigrant heritage as she watched thousands of protesters file by.

"They should be here, we need them," said Kershaw, a bedding designer. At the same time, however, she said the rallies were unnecessary and "will do [immigrants] harm."

Nancy Heffernan of Riverside saw it very differently as she watched Monday's procession in the Loop.

"I think it's about time people in this country started standing up," Heffernan said. "My ancestors were immigrants and I'm sure they weren't all legal."

Barton Haneberg, perched outside the Dirksen U.S. Courthouse as the marchers passed by, said his wife is from Spain and is navigating a bureaucratic maze to gain permanent permission to remain.

"I just feel that so many people are so confused about the issue that they don't even know what they are asking for," Haneberg said. "This doesn't get much of a message across. It's just a show of force."